1. Field of the Invention
The present invention relates to a curtain wall construction.
2. Prior Art
It is known to put backup bars between adjacent ones of the panel units of a curtain wall and apply a caulking compound to the backup bars so as to fill up the seams. FIG. 12A of the accompanying drawings shows one such structure in which the backup bars that meet at an intersection are separate and subjected to deformation and damage when the panel units become displaced as illustrated in FIG. 12B. Accordingly, the applied caulking compound has become cracked or broken due to such displacement of the panel units, with the result that dust and water have entered through the cracks in the caulking compound into the building wherein they could impair floors and ceilings.